The present disclosure relates generally to genetically modified plants, and more particularly to methods of using genetically modified crop plants to control the negative effects of certain disease-causing organisms in crop plants.
Members of the saprophytic fungus genus Aspergillus produce aflatoxin, a strictly regulated and highly carcinogenic metabolite in plants. Alfatoxin-producing members of Aspergillus include A. flavus, which commonly afflicts many important food crops including the cereal crops maize, sorghum, pearl millet, rice, wheat, and oilseeds including peanut, soybean, sunflower and cotton. A. flavus causes ear rot on corn that results in aflatoxin contamination and the presence of aflatoxin results in a large loss of marketable crop by farmers each year.
The native habitat of Aspergillus is in soil, decaying vegetation, hay, and grains undergoing organic decay. It commonly invades all types of organic substrates whenever favorable growth conditions exits. Favorable conditions include a relatively high (7% or higher) moisture content and higher ambient temperatures. Thus, A. flavus is widely present under common crop field and storage conditions, and can threaten significant contamination of a crop before harvest or in storage. Moreover, host crops are more susceptible to Aspergillus infection and resulting aflatoxin contamination under stressful growing conditions, including drought. At this time, few options are available for effective control of this pathogen. Breeding programs to generate aflatoxin-resistant cultivars of agricultural significance have not met much success. A need remains for methods to prevent and control aflatoxin contamination in the field.